This invention relates generally to the construction of food sauce dispensing cartridges and more particularly to a method and apparatus for constructing the dispensing end portion of the cartridge.
In fast service restaurants and other food service facilities, various types of food sauces are applied to sandwiches and other foods. Because fast service restaurant chains in particular serve a large volume of customers, it is necessary for the sauces to be dispensed in carefully controlled portions, each of which contains a relatively small amount of sauce that is equal in volume during each dispensing cycle. It has proven to be convenient in applications of this type for the sauces to be packaged in dispensing cartridges from which the sauce is dispensed using handheld dispensing guns. The amount of sauce that is dispensed is controlled by providing suitable valving in the dispensing end of the cartridge and using a dispensing gun that advances a plug in the cartridge a consistent distance each time the trigger of the dispensing gun is squeezed.
Examples of the types of dispensing cartridges that have been used include U.S. Pat. No. 4,432,473 to MacEwen and U.S. Pat. No. 4,830,231 to Smith. While this type of dispensing cartridge has functioned well for the most part, it has been found that the construction of the end disk and its connection with the body of the cartridge can be improved.
In the past, it has been common practice to use xe2x80x9chot meltxe2x80x9d adhesive to glue the end disk in place inside the end of the cartridge. Adhesives of this type are normally applied to the inside surface of the disk and cartridge wall where they are in contact with the food sauce that is contained in the cartridge. Consequently, the adhesive must meet food grade standards. Such adhesives are relatively expensive and complicate the manufacturing process because the adhesive must be heated and applied accurately. The adhesive is typically applied in a bead or fillet that must be continuous around the entire periphery of the disk in order to prevent leakage of sauce past the edge of the disk. The raw edge of the disk must be isolated from the food sauce by the adhesive so that the food sauce is prevented from xe2x80x9cwickingxe2x80x9d into the paperboard edge of the disk. Problems have also been encountered because many of the adhesives that are applied do not exhibit good temperature or chemical resistance properties, thereby limiting the type of products that can be packaged in and dispensed from the cartridge. In the past, the end disk has usually been recessed a significant distance inwardly from the end of the cartridge body. This makes the volume of the cartridge body that is located beyond the disk unavailable to hold the sauce, and the capacity of the cartridge is limited accordingly. When pressure is applied during dispensing of the sauce, the end disk can deflect and thus create problems such as splattering or a variation in the amount of sauce that is dispensed from cycle to cycle.
Concurrently with the present invention, an improved end construction has been developed for dispensing cartridges that hold food sauces and other foods. In the improved end construction, the end disk of the cartridge has a peripheral skirt that is folded back on itself when a flange on the end portion of the cartridge body is crimped against the outer surface of the end disk and heat sealed in place. The raw edge of the disk is isolated from the food sauce because it is enclosed between the flange and disk. Also, a stronger end construction is provided due to the double thickness that results from the folded over skirt and also the additional layer that results from crimping of the flange along the peripheral portion of the disk. Other advantages are achieved as well.
The present invention is directed to a method and apparatus for effectively and reliably producing an end construction of this type in an economical manner. More particularly, it is an object of the invention to provide a method and apparatus that involves forming a peripheral skirt on an end disk, inserting the disk into an open end of a cartridge body to a selected location, crimping the end portion of the cartridge body to form a flange which folds the skirt on the disk in order to provide a double over lip on the peripheral area of the disk, and heat sealing the flange such that the lip and its raw edge are enclosed and sealed between the flange and disk. This method of forming the end avoids the expense of xe2x80x9chot meltxe2x80x9d adhesives which have been used in the past to glue the end disk in place in this type of food container.
In accordance with the invention, the disk may be initially provided in a planar form and held in a transfer pocket. A disk punch is activated to move the disk from the transfer pocket through a die opening that is smaller in diameter than the disk. As a result, the periphery of the disk is folded or bent at a right angle to form a peripheral skirt on the disk. The die may have two portions which successively decrease in diameter to facilitate the formation of the skirt.
The disk punch continues its operation to insert the disk into the open dispensing end of the cartridge body and against a mandrel that provides a stop for properly locating the disk in the cartridge. With the mandrel holding the disk in place, a crimping device deforms the end portion of the cartridge body inwardly to form a flange which is folded against the disk. As the flange is bent inwardly from the cartridge body, it folds the skirt against the disk to provide a doubled over lip on the peripheral area of the disk.
Immediately prior to the crimping operation, heat may be applied to melt thermoplastic coatings on the cartridge body and disk. When the parts are crimped together, the thermoplastic creates a bond between them and results in the plastic creating a weld and sealing the disk periphery to the sidewall of the cartridge. The lip and its raw paperboard edge are thus enclosed and sealed between the flange and disk so that the paperboard edge is isolated from the food sauce held in the cartridge.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.